A new Window will show you all the firmware files present in the flashtool firmware folder on the left side. Select the FTF you just downladed.

On the right of the window, under Wipe, tick DATA, CACHE, and APPSLOG. If you’re using flashtool v0.9.19.10 and older, make sure you tick the SIMLOCKoption as well. For newer versions of flashtool, make sure SIMLOCK is unticked.Download and Flash Sony Xperia E Dual C1604 Original Firmware (ROM)

Download and Flash Sony Xperia E Dual C1604 Original Firmware (ROM)

Click Flash.

Download and Flash Sony Xperia E Dual C1604 Original Firmware (ROM)

Preparing files can take while. Sometimes more than a couple of minutes even. Once it is done, however, you will be prompted to connect Sony Xperia E Dual C1604.

Sony Xperia E Dual C1604 needs to be connected in Flashmode. So turn it off, then press and hold the Volume Down button when connecting the USB cable to Sony Xperia E Dual C1604. The LED on Sony Xperia E Dual C1604 should light up in green. Download and Flash Sony Xperia E Dual C1604 Original Firmware (ROM)

Download and Flash Sony Xperia E Dual C1604 Original Firmware (ROM)

If you connected Sony Xperia E Dual C1604 correctly, the flashing should begin. Make sure the connection is not loose. Sometimes a corrupt FTF can also cause the process to fail.

The flashing can also take a while depending on Sony Xperia E Dual C1604, the USB port, and the cable.

Once it is finished, you will see the message displayed on flashtool.

Download and Flash Sony Xperia E Dual C1604 Original Firmware (ROM)

Do what the flashtool says, unplug Sony Xperia E Dual C1604 and turn it on. Your new, or old, Sony Xperia E Dual C1604 stock firmware should be ready to boot up. The first boot is always the longest, and you might have to wait a couple of minutes.